If you use the CMOS version:
  http://www.radioshack.com/product/index.jsp?productId=2062595
you don't have to come up with a 5 V supply.  You can run it on
automotive "12 V" and it's less sensitive to noise.
  Of course the R*dio Sh*ck info doesn't really tell you this.

This chip has been working fine for a few years to produce the fake
VSS signal for my Subie conversion.

Larry A.

On Thu, Apr 21, 2011 at 1:49 PM, neil n <musomuso@gmail.com> wrote:
> Interesting idea. Beats the heck out of trying to reverse engineer a
> GM On Star unit into my Westy. � ;)
>
> Seems there's lots of used for that timer.
>
> http://www.555-timer-circuits.com
>
> Neil.
>
> On Thu, Apr 21, 2011 at 10:30 AM, David Beierl <dbeierl@attglobal.net> wrote:
>> At 04:12 PM 4/20/2011, neil n wrote:
>>>
>>> *switch would be labelled "Angry" and "Happy" just to confuse the next
>>> guy. � ;)
>>
>> If you want to get fancy - it's been demonstrated that the most effective
>> way to get attention (and help track position?) for emergency is four per
>> second repetition...just the thing for a 555 timer and relay circuit.
>>
>> Yrs,
>> d
>>
>
>
>
> --
> Neil Nicholson '81 VanaJetta 2.0 "Jaco"
>
> http://tubaneil.googlepages.com/
>
> http://groups.google.com/group/vanagons-with-vw-inline-4-cylinder-gas-engines
>